High-pressure steam-generator



(No Model.) 2 Sheets Sheet 1.

E. T. SEDEEHOLM. HIGH PRESSURE STEAM GENERATOR.

No. 557,899. PatentedApr. 7, 1896.

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E. T. SEDERHOLM.

HIGH PRESSURE STEAM GENERATOR.

No. 557,899. Patented Apr. '7', 1896.

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UNITED STATES PATENT OFFICE.

EDIVARD T. SEDERIIOLM, OF GIIICAGO, ILLINOIS.

HIGH-PRESSURE STEAM-GENERATOR.

SPECIFICATION forming part of Letters Patent No. 557,899, dated April 7, 1896.

Application filed July 1, 1895. Serial No. 554,559. No model.)

To all whmn it may concern:

Be it known that LEDwAnn T. SEDERHOLM, of Chicago, in the county of Cook and State of Illinois,have invented certain new and useful Improvements in High-Pressure Steam- Generators; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will en able others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

The main objects of my invention are to rapidly generate dry steam under high pressure within a small space or compass, andin the attainment of that end to promote circulation, to provide ample water-surface, and to avoid the exposure of the downward watercurrent connections of the boiler to the fire.

It consists of certain novel features in the construction and arrangement of the component parts of the boiler or generator, as here inafter particularly described, and pointed out in the claims.

In the accompanying drawings like letters designate the same parts in the several figures.

Figure l is a partial vertical cross-section and a partial front elevation of a steam boiler or generator embodying my improvements. Fig. 2 is a vertical longitudinal section of the boiler, and Fig. is a cross-section of a modified form.

The boiler herein shown and described is intended principally for central stations, or places where a large amount of power has to be crowded into a small space. At present water-tube boilers are about the only ones used for such purposes, on account of the small space they occupy, as well as on account of the high pressures at which they may be worked; but water-tube boilers are neither economical in operation nor do they give off dry steam. They lack suflicient water-surface, and they are so constructed that the flame strikes cool surfaces much too soon, making it impossible to burn bituminous coal to advantage. To overcome these difficulties and secure the objects hereinbefore stated is the design of my improvements.

Referring to Figs. 1 and 2 of the accompanying drawings,A designates a fire-tube boiler similar to those in common use, except that it is made of larger diameter in proportion to its length and is furnished with a greater number of fire-tubes a a. It is also constructed of thick heavy plates to withstand the high pressure to which it is designed to be subjected. The tube-heads above the firetubes to amay be connected with tie-rods a a.

B designates the furnace, which may be constructed in various ways, according to the conditions and requirements under which the boiler is to be used. It is shown as provided in the present case with a fire or bridge wall I); but this may be dispensed with. At the rear end it opens into a flue-space O, which communicates with the rear ends of the firetubes at a of the upper main portion of the boiler. At their front ends the fire-tubes open into a smoke-box D, which communicates in the usual way with a smoke-stack or chimney. (Not shown.)

Between the furnace and main boiler-shell A, I interpose a number of shells E E of smaller diameter, arranged transversely to the shell A, close together, side by side, which may be supported at the ends in or upon the side walls of the furnace. These shells are made arching, or higher at the center than at the ends, and are constructed of thinner lighter boiler-plate, being of much smaller diameter than the main shell A, and consequently able to withstand as great internal pressure even if made of lighter material. They are connected at or near their ends by pipes F F, and at the center or highest points therein by pipes G G, with the main shell A, below the water-level therein. These connections, communicating with the shells E E at different levels, compel the water when heated to circulate through them and the upper shell, thereby greatly facilitating the generation of steam, the hotter currents, with steam produced in the shells E E, passing upwardly through the central pipes G into the upper shell between the firetubes a a, and the cooler currents passing thence downwardly through the side pipes F F, as inclicated by arrows.

The shells E E, constituting a hollow water roof or arch over the furnace, protect the under side of the upper shell A and its connections with said water-roof from direct ex- ICO posure to the fire, the joints between them being closed by metallic bars or other fireproof material in any suitable manner. It is well known that steam-bubbles tend to form and rise from the inside of boiler-plates which are exposed on the outside directly to the action of fire. The formation and ascent of such bubbles in the down-current connections between the main shell A of the boiler and the water-roof would tend to retard the circulation. Therefore I prefer to exclude the fire or direct heat from the furnace from the pipes F F.

The shells E E being made of thinner plates than the main shell A by reason of their smaller diameter, as above stated, and being exposed on their under side directly to the fire, the water is quickly heated and partially evaporated, and passing upwardly through the pipes G G into the upper shell A comes in contact with the heated surfaces of the firetubes a a and is rapidly converted into steam, which is given ofi from the extended watersurface in the upper portion of said shell A above the fire-tubes. The upper shell A being of large diameter affords an extended water-surface and admits of the production of dry steam.

To produce a longitudinal circulation of the water through the boiler, the side pipes F F on one side may be inclined forwardly and those on the opposite side rearwardly, as shown, or the connections between the upper shell and water-roof may be staggered transversely to the boiler in any convenient way. These connections may also be staggered lengthwise of the boiler to avoid weakening the shell A.

The ends of the shells or drums E E preferably project through and are exposed outside of the side walls of the furnace and are provided at either or both ends with openings 6' e, which are ordinarily closed in the usual manner by covers (not shown) for facilitating access to the interior of said shells and the removal therefrom of scale and sediment which accumulate and are held in their lower ends, the arching shape of the shells E E or water-roof tending to carry and deposit scale and sediment in their outer ends, where they do not interfere with the operation of the boiler. The central connections G G with the main boiler-shell A may also serve for the removal of sediment.

I do not wish to be understood as limiting myself to the construction shown in Figs. 1 and 2 of the water-roof, as it may be made in various ways. For instance, it may be constructed of plain plates, like the water-leg of a locomotive-boiler, connected and braced by tie-bolts, or it may be made of straight cylindrical shells placed side by side lengthwise of the boiler.

In Fig. 3, illustrating a modification of the boiler in which the current takes the opposite direction from that shown in Figs. 1 and 2, the water-roof is composed of a number of the shells E toward their outer ends, into which scale and sediment are carried and deposited. By thus reversing the direction of circulation the water-roof need not be arched or made higher at the center to avoid the deposit of scale and sediment therein over the surfaces exposed to the greatest heat, since the outward current will sweep all scale and free impurities into the ends of the shells E, from which they can be removed from time to time through the opening 8 e.

I claim 1. In a steam boiler or generator the com bination with a fire-tube boiler and a furnace communicating with the fire-tubes at one end of the boiler, of a hollow water-roof interposed between said boiler and furnace and separating the boiler-shell and its connections with said water-roof from the furnace and flue-space, and separate up and down current connections between said water-roof and boiler, communicating at a distance from each other with the boiler-shell below the water-level therein and with said water-roof at difierent levels, so as to induce circulation of the water up and down through said connections and back and forth horizontally in said water-roof and boiler, substantially as and for the purposes set forth.

2. The combination with a fire-tube boiler and furnace, of an arch-shaped water-roof interposed between said furnace and boiler and having connections at or near the center and on each side thereof with saidboiler, below the water-level therein, said connections communicating with said water-roof at different levels and at a distance from each other, substantially as and for the purposes set forth.

3. The combination with a horizontal firetube boiler and furnace, of a water-roof composed of shells of smaller diameter than the boiler, arranged transversely side by side between the boiler and furnace, and having connections with said boiler below the waterlevel therein, said connections communicating with said water-roof at different levels and at a distance from each other, substantially as and for the purposes set forth.

4. The combination with a horizontal firetube boiler and furnace, of a water-roof interposed between said boiler and furnace and having connections with said boiler below the water-level therein, said connections communicating at a distance from each other and at different levels with said water-roof and being inclined lengthwise of the boiler in opposite directions so as to produce a longitudinal circulation therein, substantlally as and for the purposes set forth.

5. The combination with a horizontal firetube boiler and furnace, of a water-roof composed of shells of smaller diameter arranged transversely side by side between said boiler and furnace, and exposed at the ends, which are provided with openings outside of the furnace-walls and connections between said water-roof and boiler communicating with the boiler-shell below the water-level and with the water-roof at a distance from each other and at different levels, substantially as and for the purposes set forth.

6. The combination with a horizontal firetube boiler and furnace, of a water-roof composed of arch-shaped shells of smaller diameter than the boiler, placed side by side transversely between the boiler and furnace and exposed at their ends, which are provided with openings outside of the furnace-walls and connections between the middle or highest parts of said shells, and on opposite sides thereof and at lower points therein with the boiler below the water-level, substantially as and for the purposes set forth.

'7. The combination with a horizontal firetube boiler having a thick cylindrical shell and numerous tubes extending lengthwise through it and a furnace communicating with said tubes at one end of the boiler, of a water-roof composed of thinner shells of smaller diameter placed side by side transversely between said boiler and furnace and separating the boiler-shell and its connections with the water-roof from the furnace and flue-space,

'and connections between said boiler and wa- EDWARD T. SEDERHOLM. YVitnesses:

THOS. W. CAPEN, GREGOR MoGREcoR. 

